Everything You Need to Know about Narcissists, Psychopaths, and Abuse - click on this link: http://www.narcissistic-abuse.com/faq1.html
I have written the bible about psychopathic narcissists twenty odd years ago. Yet, when I come across one, I am shaken to my foundations. There is something utterly reptilian or alien about them.
Psychopathic narcissists - and histrionic and borderline women - are driven by primitive urges, unrequited needs, raw negative impulses (like rage and vindictiveness) and psychological defense mechanisms run amok and awry. It is not so much a lack of empathy as it is a one track mindedness that renders them robotic and zombie-like.
You cannot contract with a psychopathic narcissist or with a histrionic borderline woman: they recognize no rules, have no deep emotions, get attached to no one, play mind games with everyone, and lie incessantly. They will not hesitate to hurt you fatally if it gratifies the triflest of their wishes. They are not sadists: you are mere collateral damage.
Where a human being should be, there is a vast deep space of emptiness with howling, primordial winds.
These defective renditions of humans have no spouses and know no children, maintain no friendships and keep no families. They plough through their lives and the lives of their "nearest and dearest" like unstoppable and unconscionable wracking balls, swinging apathetically between compulsions and obsessions and the ever more dimming awareness of the stirrings that pass for their consciousness.
(From the book "Malignant Self-love: Narcissism Revisited" by Sam Vaknin - Click on this link to purchase the print book, or 16 e-books, or 3 DVDs with 16 hours of video lectures on narcissists, psychopaths, and abuse in relationships: http://www.narcissistic-abuse.com/thebook.html)